Circuit for telephone auxiliary exchanges having delayed connection of a busy signal set

Abstract

A busy signal connecting set is immediately released by the disengagement of a connecting station participating in an existing connection, and a state of interception is established for the subscriber circuit of the subscriber station which has not yet released. The subscriber circuit is connected with a house set for the purpose of connecting the busy signal by way of time switching equipment which is activated after a delay time in response to production of the state of interception.

We claim: 
     
       1. In a telecommunications exchange system in which, in response to a release signal produced as a result of a subscriber station releasing an existing connection, a connection set of the system seized for that connection is immediately released, in which the system includes internal connection sets, and in which a central control device of the system establishes an intercept state engaging the subscriber circuit of another subscriber station involved in that connection and not yet released, the improvement therein comprising: delay means in said subscriber circuit; and   switching means in said subscriber circuit connected to said delay means and operable in response to the establishment of the intercept state, delayed by said delay means, to send call signals to the central control device which is responsive to the call signals to establish a connection of the subscriber circuit to a free internal connection set of the system, as would normally be the case in an outgoing seizure of the subscriber circuit, for connection of a busy signal instead of dial tone to the subscriber circuit not yet released via the just-connected internal connection set.